The Best Underlayment for Metal Roofing: Why It Matters

Building a Strong Foundation for Your Roof

When it comes to metal roofing, the panels themselves often get the spotlight. But one of the most important components of any roofing system is what’s underneath: the underlayment. Acting as a protective barrier between your roof deck and the metal panels, underlayment plays a critical role in performance, energy efficiency, and longevity. Choosing the right type of underlayment can make all the difference in how well your roof holds up against the elements.

Traditional Felt Underlayment

Felt underlayment, also known as tar paper, has been used for decades. It’s typically made from a paper or fiberglass base saturated with asphalt. While affordable and effective in certain applications, felt comes with limitations:

• Shorter lifespan – Felt can tear or degrade more quickly under heat and moisture.
• Heavier weight – It can be more difficult to install compared to newer alternatives.
• Less water resistance – Once saturated, it loses much of its ability to protect against leaks.

Felt may be suitable for budget-conscious projects, but it’s generally not the best match for the long life expectancy of metal roofing.

Synthetic Underlayment

In recent years, synthetic underlayment has become the preferred option for metal roofing. Made from advanced polymers, it offers a range of advantages:

• Superior durability – Resistant to tearing, UV exposure, and temperature swings.
• Lightweight design – Easier to handle and install, often with non-slip surfaces for added safety.
• Enhanced water resistance – Provides a stronger shield against moisture infiltration.
• Longer lifespan – Better aligned with the decades-long durability of a metal roof.

Because metal roofs can last 40–70 years, pairing them with a high-performance synthetic underlayment ensures the entire system works together for maximum protection.

Why the Right Underlayment Matters

Your roof is only as strong as its foundation. Underlayment helps prevent leaks, adds an extra layer of insulation, and provides peace of mind in case of severe weather. For homeowners investing in metal roofing, choosing synthetic underlayment is a smart way to protect that investment and extend the life of the roof system.

Protect Your Home with the Right Roofing System

At The Metal Roofers, we don’t just install metal roofs.   We install complete systems designed to perform for decades. From the panels to the underlayment, every detail matters. Contact us today for a free inspection and estimate, and let’s make sure your roof is built to last.

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